Furnace



Aug. 12, 1941. w. l.. STEELE FURNACE Filed Oct. 17, 1958 ATTO R N EYS`nace. w

suitable refractory material and is located at Patented Aug. 12,1941

I PATENT oFFl-CE d FUnNA'cE d William L. Steele, Seattle, Wash. v yApplication October 17, 1938, Serial No. 235,535

6 Claims.

My invention relates to the art of burning gaseous fuel for theproduction of heat'for heating homes and the like, and has among itsobjects and advantages the provision of an improved furnace of the hotair type.

'I'he present application is a continuation lin part of my patentedapplication led June 22, 1937, Serial No. 149,742, now Patent No.2,144,129, issued January 17, 1939. Y

Conventional heating-furnaces of the hot air type employ a combustionchamber located against the heating surface or shell -of the furnace. Asa rule, the lower area of the furnace shell is lined with refractorymaterial throughout the combustion chamber area. In construcin beingplaced against the shell proper, pracn tlcally eliminates the portioncovered as heating area. Accordingly, an object of my invention is toprovide a furnace so constructed as to greatly increase the heating areain a shell of given size and in which the construction is such as togreatly increase the heat absorption of the furnace.

More specifically, it is a further object of .my invention to provide aburner or combustion chamber locatedinside the furnace proper in spacedrelation with the furnace shell, thereby greatly increasing'the heatingarea of the fur- The combustion chamber is lined with the bottomeof thefurnace proper. It is a well known fact that the bulk of the heat from aluminous flame such as an oil fire is radiant heat. My combustionchamber is .so related to the furnace shell that the greater area of theheating surface ofthe shell is directly exposed to radiant heat from thelire. I arrange the combustion chamber inside the furnace in such manneras to permit down-draft circulation of the hot gases or burnt productsof combustion.` The flue outlet is located at the bottom of the furnace,and the combustion chamber extends upwardly from the furnace bottom. Tothe top of the combustion chamber, I attach a baffle so designed thatthe space between the baffle and the furnace is of the same area as theflue outlet. This compels the down-going hot gases to pass evenly allaround the baille, thereby heatlng the furnace shell uniformly all theway around. Accordingly, I provide a furnace of the -hot air typewherein hot spots or overheated areas. are eliminated. The baliie, incombination with the location of the outlet ue, slows down the heattravel through the furnace in such degree as to greatly increase theheat absorption of the furnace. Absence of' the baille or equivalentmeans would cause the ue outlet to draw a major portion of the hot gasesto the side where the flue leaves the furnace body. My inventioneliminates such unequal heat distri'- bution.

A further object is to provide a waterheatingv coil arranged in heattransfer relation withthe In the embodiment selected te illustrate myinvention, the furnace lll comprises an upright shell l2 preferablycircular in cross section. The top I4 is flanged at I6 and the flange issecured to. the shell I2 in the usual manner, as by rivets I8.v Thelower end of the shell l2 is provided with -a bottom flanged and rivetedat 22 to the shell. Legs 24 support the furnace proper in an uprightposition.

Inside the shell of the furnace, I mount a burner or combustionv chamber26 in the nature of a fire pot, which comprises a circular'me-v tallicshell 28 preferably arranged concentrically with the shell I2. I providethe shell 28 with a lining 30 of refractory material such as is commonlyused in furnace structures. The bottom 20 extending across thecombustion chamber is also provided with refractory material. An oil 40burner unit 32 provided with a conventional nozzl'e 34 extends throughthe shells l2 and Z8 for delivering the fuel spray 36 into thecombustion chamber 26. A flue outlet 3l communicates with the shell l2near the bottom 2u. Flue outlet :3l delivers the burnt products ofcombustion to the ue 38 for escape to the atmosphere.

The wall structure of the combustion chamber 26 is spaced from the shelli2 so as to utilize the otherwise covered furnace area for additionalheat absorption surface lin the furnace proper. Combustion chamber 26 isopen at its top and is located at the bottom of the furnace so that thelarger part of the heating surface is directly exposed to the radiantheat from the fire. The 56 hot gases move upwardly and then sweepdownthe top of the combustion chamber, and the space between thedown-turned flange 44 and the shell I2 is of the same area as the crosssectional area of the flue outlet 3l. Thus the area of the space betweenthe ring and the shell l2 compels the down-going hot gases to passevenly all around the baffle, thereby heating the surface area equallyall the way around. Thus my furnace structure is devoid of the hot spotsor overheated areas that occur in other furnaces of the hot air type.The down-draft feature slows down the travel of the products ofcombustion, thus allowing more timel for heat absorption. The closeproximity of the baille to the furnace wall compels equal heatdistribution over the entire furnace.

The construction is exceedingly simple, while the arrangementvof theparts is such as to provide a highly eflicient furnace. The simplicityof the design makes the furnace very economical to build.

Means are provided for heating domestic water. In Fig. 1,v I illustratea flue outlet 46 as having communication with the combustion chamber 26and venting into the ue 38. The

cold water line 48 passes through the flue 46 and.V

is connected with a coil 5G, the other end of which is connected withthe hot water outlet pipe 52. Flue outlet Slis provided with a rotarydamper 54, while flue outlet d5 is provided with a similarly mounteddamper 56. Damper 54 is .connected with an arm 58, while damper 55 is vconnected with an arm 55. Both arms are pivotally connected with a bar52 which may be connected with a pull chain GQ permitting adjustment ofthe dempers from a remote position. Thus the dampers 54 and 55 areconnected for simultaneous movement, but the operating linkage is sodevised as to fully open the damper 5d as the damper 55 is fully closed.

During winter months when the furnace is employed for house heatingpurposes, the damper 56 is maintained closed since the heavier fireemployed during such months is suciently hot to heat the coil 50 to sucha degree as to maintain a sufficient supply of hot water. At times thehot water demand may be exceptionally heavy so as to necessitate slightopening of th valve 56. In any event, the total flue outlet area remainsthe same even though both the dampers are partly open. It will thus beseen that the coil 50 may be additionally heated while at the same timemaintaining a balanced fiue outlet area with respect to the passageareabetween the flange 44 and the shell i2.

Without further elaboration, the foregoing will so fully illustrate myinvention that others may, by applying current knowledge, readily adaptthe same for use under various conditions of service.

I claim:

1. A furnace 'comprising a shell, a combustion chamber open at its upperend located at the bottom of the shell and spaced from its side walls,to provide a down-draft passage for burnt products of combustion,meansfor delivering fuel to the combustion chamber, said shell having anoutlet flue near its bottom of a 'cross sectional area. substantiallyequal to the cross sectional area of the down-draft passage, asecond'outlet ue of the same cross (sectional area as said rst outletflue leading into the combustion chamber only, a water heating coil insaid second outlet flue, damper means in each of -the outlet ues, andoperating means interconnecting the damper means, one of the dampermeans being totally closed when the other damper means is totally open,said operating means being so constructed and arranged as to open onedamper means while closing the other damper means in the same degree. ,A

2. A furnace comprising a shell, a combustion chamber 'open at its upperend located at the bottom of the shell in spaced relation with thelatter, to provide a down-draft passage for burnt products ofcombustion, means for delivering fuel to the combustion chamber, abaille extending laterally of the combustion chamber in spaced relationwith said shell, to provide a restricted down-draft passage, said shellhaving an outlet ue near its bottom of a cross sectional area equaltothe cross sectional area of the rev stricted down-draft passage, asecond outlet flue of the 'same cross sectional area as said firstoutlet )flue leading into the combustion chamber only, a waterheatingcoil in said second outlet.

3. A furnace comprising a radiant heat ab- I sorbing shell, a refractorylined combustion chamber open at its upper end located at rthe bottom ofthe shell and spaced from its sides, to

' provide a down-draft passage for burnt prodeil ` enclosing shellhaving an annular side wall; an

ucts of combustion, means for delivering fuel to the combustion chamber,said sfhell having an outlet flue near its bottom of a cross sectionalarea substantially equal to the Ycross sectional area of the down-draftpassage, a second outlet flue of the same ycross sectional area as saidfirst outlet flue leading into the combustion chamber only, a waterheating coil in said second outlet flue, damper means in 'each of theoutlet nues, and operating means interconnecting the damper :meanaloneof the damper means being totally closed when the other damper means istotally open, said operating means being so constructed and arranged asto open one damper means while closing the other damper means in thesame degree.

4, A furnace for fluid fuel, comprising: an enclosing shell; an open-topfire pot located inside the shell at its bottom and spaced from the sideWalls thereof to provide a smoke passage extending about the verticalWalls of the fire pot; said fire pot terminating well below the the firepot; and means coactingwith the side walls of said shell to define anunobstructed smoke passage between the top margin of the re pot and theside walls of said shell, entirely surrounding the fire pot at the topmargin, and of an effective area substantially equal to thecross-sectional area of said liuc.

5. A furnace for iiuid fuel; comprising: an

open-top iire pot located inside the shell at its bottom and having anannular vertical Wall mesme speced from the side Wall of the shell toprovide an annuler smoke passage between the re pot and the shell; seidre pot terminating well below the top Well of the shell, to eiord itsonly communication with the interior of the shell: e. flue communicatingwith said smoke passage be low the top of the fire pot; and a angedisposed r between the re not and seid shell above said Hue to provideun unobstructed annular smoke passage of an effective area-substantiallyequal to the cross-sectional nieu of seid flue and of equal eiectivedown-draft throughout, to uniformly distribute burnt products ofcombustion throughout seid first-'mentioned smoke passege.

6. A furnace for uid fuel, comprising: en enclosing shell; en open-tonme pot located in side the shell et its bottom and spaced from thel sidewells ther-eci? to )provide a smoke sssee extending snout the verticalside walls of the me pot; seid me not terminating Well below the topwall of the shell, to uord its only communicetion with the interior ofthe shell; e, flue communicetine with seid passage below the top of there not: and the upper margin of seid re not sleeve seid fiue beine soconstructed end erranged end enacting with the side walls of the shellns to define en unobstructed smoke message between the ton) margin ofthe re mt und the side wells ci seid shell, entirely surrounding the menot et its tcp meinem, snol of en effective

